Wiktionary
clone town
n. (context British English) A town whose major shopping areas are dominated by chain stores at the expense of local diversity.
Wikipedia
Clone town
Clone town is a global term for a town where the High Street or other major shopping areas are significantly dominated by chain stores. The term was coined by the New Economics Foundation (NEF), a British think tank, in the 2004 report on "Clone Town Britain".
A survey conducted by the NEF in 2005 estimated that 41% of towns in the UK and 48% of London villages could be considered clone towns, with the trend rising.